/*
** $Id: lparser.h,v 1.57.1.1 2007/12/27 13:02:25 roberto Exp $
** Lua Parser
** See Copyright Notice in lua.h
*/

#ifndef lparser_h
#define lparser_h

#include "llimits.h"
#include "lobject.h"
#include "lzio.h"


/*
** Expression descriptor
*/

typedef enum
{
    VVOID,	/* no value */
    VNIL,
    VTRUE,
    VFALSE,
    VK,		/* info = index of constant in `k' */
    VKNUM,	/* nval = numerical value */
    VLOCAL,	/* info = local register */
    VUPVAL,       /* info = index of upvalue in `upvalues' */
    VGLOBAL,	/* info = index of table; aux = index of global name in `k' */
    VINDEXED,	/* info = table register; aux = index register (or `k') */
    VJMP,		/* info = instruction pc */
    VRELOCABLE,	/* info = instruction pc */
    VNONRELOC,	/* info = result register */
    VCALL,	/* info = instruction pc */
    VVARARG	/* info = instruction pc */
} expkind;

typedef struct expdesc
{
	expkind k;
	union
	{
		struct { int info, aux; } s;
		lua_Number nval;
	} u;
	int t;  /* patch list of `exit when true' */
	int f;  /* patch list of `exit when false' */
} expdesc;


typedef struct upvaldesc
{
	lu_byte k;
	lu_byte info;
} upvaldesc;


struct BlockCnt;  /* defined in lparser.c */


/* state needed to generate code for a given function */
typedef struct FuncState
{
	Proto* f;  /* current function header */
	Table* h;  /* table to find (and reuse) elements in `k' */
	struct FuncState* prev;  /* enclosing function */
	struct LexState* ls;  /* lexical state */
	struct lua_State* L;  /* copy of the Lua state */
	struct BlockCnt* bl;  /* chain of current blocks */
	int pc;  /* next position to code (equivalent to `ncode') */
	int lasttarget;   /* `pc' of last `jump target' */
	int jpc;  /* list of pending jumps to `pc' */
	int freereg;  /* first free register */
	int nk;  /* number of elements in `k' */
	int np;  /* number of elements in `p' */
	short nlocvars;  /* number of elements in `locvars' */
	lu_byte nactvar;  /* number of active local variables */
	upvaldesc upvalues[LUAI_MAXUPVALUES];  /* upvalues */
	unsigned short actvar[LUAI_MAXVARS];  /* declared-variable stack */
} FuncState;


LUAI_FUNC Proto* luaY_parser(lua_State* L, ZIO* z, Mbuffer* buff,
                             const char* name);


#endif
